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| author | Paul Kirth <paulkirth@google.com> | 2024-01-23 14:04:52 -0800 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2024-01-23 14:04:52 -0800 |
| commit | 9d476e1e1a18af390e3455a6622ee67a69c64103 (patch) | |
| tree | f4dfc7844153746db48b935dd4123f1d64cf7bd4 /llvm/lib/Passes/PassBuilderPipelines.cpp | |
| parent | a829f109ffd518230df5191c64aa427603cf10d9 (diff) | |
| download | llvm-9d476e1e1a18af390e3455a6622ee67a69c64103.zip llvm-9d476e1e1a18af390e3455a6622ee67a69c64103.tar.gz llvm-9d476e1e1a18af390e3455a6622ee67a69c64103.tar.bz2 | |
[clang][FatLTO] Avoid UnifiedLTO until it can support WPD/CFI (#79061)
Currently, the UnifiedLTO pipeline seems to have trouble with several
LTO features, like SplitLTO units, which means we cannot use important
optimizations like Whole Program Devirtualization or security hardening
instrumentation like CFI.
This patch reverts FatLTO to using distinct pipelines for Full LTO and
ThinLTO. It still avoids module cloning, since that was error prone.
Diffstat (limited to 'llvm/lib/Passes/PassBuilderPipelines.cpp')
| -rw-r--r-- | llvm/lib/Passes/PassBuilderPipelines.cpp | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/llvm/lib/Passes/PassBuilderPipelines.cpp b/llvm/lib/Passes/PassBuilderPipelines.cpp index 525b83d..6ede863 100644 --- a/llvm/lib/Passes/PassBuilderPipelines.cpp +++ b/llvm/lib/Passes/PassBuilderPipelines.cpp @@ -1531,14 +1531,17 @@ PassBuilder::buildPerModuleDefaultPipeline(OptimizationLevel Level, } ModulePassManager -PassBuilder::buildFatLTODefaultPipeline(OptimizationLevel Level) { +PassBuilder::buildFatLTODefaultPipeline(OptimizationLevel Level, bool ThinLTO, + bool EmitSummary) { ModulePassManager MPM; - // FatLTO always uses UnifiedLTO, so use the ThinLTOPreLink pipeline - MPM.addPass(buildThinLTOPreLinkDefaultPipeline(Level)); - MPM.addPass(EmbedBitcodePass()); + if (ThinLTO) + MPM.addPass(buildThinLTOPreLinkDefaultPipeline(Level)); + else + MPM.addPass(buildLTOPreLinkDefaultPipeline(Level)); + MPM.addPass(EmbedBitcodePass(ThinLTO, EmitSummary)); - // Use the ThinLTO post-link pipeline with sample profiling, other - if (PGOOpt && PGOOpt->Action == PGOOptions::SampleUse) + // Use the ThinLTO post-link pipeline with sample profiling + if (ThinLTO && PGOOpt && PGOOpt->Action == PGOOptions::SampleUse) MPM.addPass(buildThinLTODefaultPipeline(Level, /*ImportSummary=*/nullptr)); else { // otherwise, just use module optimization |